body {
  font-family: Arial, sans-serif;
  background: #f0f0f0;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
}
.calculator {
  background: white;
  padding: 20px;
  box-shadow: 0 4px 10px rgba(0,0,0,0.2);
  align-items: center;
}
input {
  padding-right: 4px;
  padding-left: 0px;
  width: 240px;
  height: 40px;
  font-size: 20px;
  text-align: right;
  margin: 0;
  border: 1px solid #ccc;
}
.buttons {
  display: grid;
  grid-template-columns: repeat(4, 60px);
  border: #ccc;
  /* 添加分割线 */
  gap: 1px;
  background-color: #ccc;
  border: 1px solid #ccc;
  align-items: center;
}
button {
  height: 60px;
  font-size: 18px;
  background-color: #ffffff;
  cursor: pointer;
  transition: background-color 0.2s;
  /* 移除默认边框，使用gap创建分割线 */
  border: none;
}
button:hover {
  background-color: #dcdcdc;
}
.equal {
  background-color: rgb(241,134,54);
  color: white;
}
.equal:hover {
  background-color: rgb(241,134,54);
}

/* 新增：为操作符按钮设置特殊颜色 */
button[onclick*="clearDisplay"] {
  background-color: rgb(241,134,54);
  color: white;
}

button[onclick*="'+'"] {
  background-color: rgb(241,134,54);
  color: white;
}

button[onclick*="'-'"] {
  background-color: rgb(241,134,54);
  color: white;
}

button[onclick*="'*'"] {
  background-color: rgb(241,134,54);
  color: white;
}

button[onclick*="'/'"] {
  background-color: rgb(241,134,54);
  color: white;
}

/* 操作符按钮的悬停效果 */
button[onclick*="clearDisplay"]:hover,
button[onclick*="'+'"]:hover,
button[onclick*="'-'"]:hover,
button[onclick*="'*'"]:hover,
button[onclick*="'/'"]:hover {
  background-color: rgb(241,134,54);
}

.title {
  height: 30px;
  width: 244px;
  font-size: 20px;
  font-weight: bold;
  text-align: center;
  background-color: #ffff;
  padding: 0px 0px;
  border-left: 1px solid #ccc;
  border-right: 1px solid #ccc;
  border-top: 1px solid #ccc;
}